Process for manufacturing monohalogenated naphthostyril compounds



Patented Sept. 13, 1932 UNITED sr'rs PATENT "OFFICE HEINZ SGHEYER, OF FRANKFORT-ON-THE-MQIN, GERMANY," ASSIGNOR TO GENERAL ANILrnE WORKS, 11m, or vnw YORK, N11, A. CORPORATION OEDELAWABE rnocnss FOR miivurec'runme MONOHALQGENATED ivArHTHos'rYRrL COMPOUNDS 7 No Drawing. Application filed January 5, 1928, Serial No. 244,775, and in Germany January 12, 1927.

, The present invention relates to' a new process for manufacturing monohalogenated naphthostyril compounds andto new com': pounds obtainable thereby. v

According to Eckstrand (J ourn f. prakt. Chemie, Vol. 38, page 139 if.) by acting with chlorine or bromine on naphthostyril dihalo enated substitution products are obtain d containing both halogen atoms in the naphthalene nucleus.

Now I have found that by treating a naphthostyril compound of the formula:

with a salt of hypochlorous or hypobrom'ous acid N -halogenated hitherto unknown derivatives of theformula: H

oo-uy-nu nal=olor Br) N-halogenated Che'mie Vol. 88, page 172 if.) could prepare only in a complicated manner, can be manufactured according to my new process with an excellent yield in a very pure state; They are important intermediates for the production of dyestuffs and of pharmaceuti- 0211 products.

In order to further illustrate my invention the following examples are given, the parts being by weight and all temperatures in Centrigrade degrees. But I wish it to be understood that I am not limited to the particular conditions nor to the specific products mentioned therein.

Example 1 .10 parts of naphthostyril (obtainable for instance according to U. S. Patent'No. 1,646,-

290) are suspended in 400 parts of a sodium hypochlorite solution containing 7% of available chlorine and the mixture is then heated to boiling for some time. A turbulent reaction takes place and the N-chloronaphthostyril separates as a granular yellow precipitate, The new compound of the formula into such. naphthostyril compounds, as are j monohalogenated inthe nucleus and correspond probably to the formula:

OO-NH a1 (Ha1=O1 or Br) In all. of the aforesaid formulas the naphthalene nucleus may contain further substituents. The molecular rearrangement of, ;the derivatives into the nuclear substitution products may be effected either by treating them with an acid condensing agent such as concentrated sulfuric; acid glacial acetic acid, zinc chloride or by beating them as such or advantageously with the addition of a suitable diluent.

The monohalogenated naphthostyril compounds, which Eckstrand (Journ. f. prakt.

is easily soluble in theusual organic solvents. When recrystallized from alcohol, it forms compact yellow crystals, melting at 132. The concentration of the chlorinatingsoluti'on used may be varied within large limits. Instead of a sodium hypochlorite solution also other hypochlorites may be used for the process, such as a solutionof chloride of lime.

10 parts of N-chloronaphthostyril, thus obtained, are dissolved in about 180 parts of sulfuric acid 96 B. and the solution is allowed to stand for some hours at ordinary temperature. Then it is poured on ice and the chloronaphthostyril separating in yellowish flakes is isolated in the usual manner. When recrystallized from trichlorobenzene, it is obtained in the form of yellow needles, melting ab out 270 as stated by Eckstrand (l. 0.). 1G"

It corresponds probably to the formula:

oo NH 1 In order to convert the N-chloronaphthostyril one may proceed also as follows:

10 parts of N-chloronaphthostyril are dissolved in about 50 parts of monochlorobenzone and the solution is heated to boiling under reflux. After a short time the formed chloronaphthostyril begins to separate as yellow needles, which soon fill up the whole liquid. They are isolated in the usual manner. The chloron aphthostyril, thus obtained, is identical with the product described above.

Instead of monochlorobenzene, for example, toluene, trichlorobenzene or particularly glacial acetic acid may also be used .as d'il-uents, for example. In the latter case the addition ofa small amount of hydrochloric acid accelerates the reaction. When heating the N-chloronaphthostyril as such to about 140", the same reaction of chlorine transposition takes place. In an analogous manner the N- bromonaphthostyril may be produced and converted into the corresponding i-bromonaphthostyril.

Example 2 10 parts of .o-ethoxynaphthostyril of the formula;

OGNH

naphthostyril) are suspended in about 400 parts of a sodium hypochlorite solution containing 7 of available chlorine and the mixture is heated to boiling, until the reaction product, which separates at first on the surface of the liquid as an oily mass, solidifies to a granular precipitate. The new N-chloro- .5-ethoxynaphthostyril, thus obtained, corresponds probably to the formula:

oo-nm flux with 40 parts of glacial acetic acid. The d-chloro-5-ethoxynaphthostyril, thus formed, corresponds probably to the formula Hi0: I

wherein the naphthalene nucleus may contain an alkoxy group, with a salt of the group of acids consisting of hypochlorous and hypobromous acid.

2. A step in the preparation of nuclear halogenated naphthostyrils which consists in treating a compound of the general formula:

l wherein X represents hydrogen or alkoxy, with a salt of the group of acids consisting no of hypochlorous and hypobromous acid.

3. A step in the preparation of nuclear halogenated naphthostyrils which consists in treating a compound of the general formula:

wherein X represents hydrogen or alkoxy, with a sodium-hypochlorite solution containing about 7% of available chlorine.

I 4. The process which comprises treating a compound of the formula:

\ obtained in the presence wherein the naphthalene nucleus may contain an alkoxy group, with a salt of the group of acids consisting of hypochlorous and hypobromous acid and heating the N-halogenated compound thus obtained in the presence of an organic diluent.

5. The process which comprises treatlng a compound of the general formula:

wherein X representshydrogen or alkoxy, with a salt of the group of acids consisting of hypochlorous and hypobromous acid and heating the N-halogenated compound thus of an organic diluent.

6. The process which comprises treating a compound of the general formula:

wherein X represents hydrogen or alkoxy;

with a salt of the group of acids consisting of hypochlorous and hypobromous acid and heating the N -halogenated compound thus obtained in the presence of an acid organic diluent.

7. As new products N-halogenated naphthostyril compounds of the general formula:

wherein Hal means chlorine or bromine and the naphthalene nucleus may contain an alkoxy group, which products are colorless to yellowish colored crystalline substances, having a definite melting point and being soluble in the usual organic solvents.

:9. 'As new products N-chlorinated naphfhostyril compounds of the formula:

wherein the naphthalene nucleus may contain an :alkoxy group, which products are colorless to yellowish colored crystalline substances,

having a definite melting point and being soluble in the usual organic solvents.

I11 testimony whereof, I affix my signature.

HEINZ SCHEYER. 

